Train-lighting system.



No. 891,221. PATENTED JUNE 16, 1908.

J. L. WOODBRIDGE.

TRAIN LIGHTING SYSTEM.-

APPLICATION FILED JUNE 2 1. 1907.

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JOSEPH LESTER WOODBRIDGE, F PHILADELPHIA, PENNSYLVANIA.

TRAIN-LIGHTING SYSTEM.

Specification of Letters Patent.v

' Patented June 16, 1908.

Application filed June 31, 1907.; Serial No. 380,008.

To all whom it may concern: I

Be it known that I, JOSEPH LESTER WOOD- BRIDGE, aeitiz'en of the UnitedStates, and a resident of Philadelphia, in the county of Philadel hiaand State of Pennsylvania, have invented a certain new and useful Train-Lighting System, of which the following is a specification.

One object of the invention, is to provide means for obtaining twodifferent voltages from the same generator suitable respectively foroperating the ramps and charging the batteries on the cars.

Other objects are to provide automatic means for controlling the twovoltages, as

well as means for automatically connecting the generator to the trainline circuits an for transferring the batteries from the chargingcircuit to the lamp circuit.

The nature, characteristic features and sco e of the invention will bemore fully un erstood from the following description taken in connectionwith the accompanying drawings forming part hereof, and in which FigureL, is a diagrammatic view of a car.

lighting system ern odying features of the invention, and Fig. 2,illustrates the armature winding of the generator shown inln Fig. 1, a

sgstem of electric train 1 ighting is shown i 1a ammatioally. Itis o thetype commonly own as Head end system; The apparatus inclosed in therectangle Q, is installed at one point in the train where power isavailable for-driving the generator, as in the baggage car or,on

the locomotive. The a paratus shown in the rectangles P, is instal ed onthe individual cars andthis a paratus is identical on each car,correspon ing parts being represented by the same letters. Conductors'1, 2, 3, and 4, traverse the several cars and are connected between thecarsby suitable couplin s as at X and;Y.-

eferring to the a paratus in the rectangleQ, F, is the field ame and D,the armature of a direct current enerator. The field circuit is providedwit three poles S, N v and N located at equi-distant oints around thearmature periphery. E, is the commutator of this generator and' bearingupon the commutator are three brushes A, B and C. The armature windinwhich will be described later in connectlon with through the pole S, butis divided between the oles N and N If this flux is' divi ed'between Nand N the otential between the-'brushes A and C, be the same as thepotential between the brushesequally B and C. If, however, the divisionof flux between N and N is not e ual, the two otentials above mentionedbe difi'erent. he total ,flux in the 'field circuit and the division ofthis 'flux between the poles N and N are controlled by three fieldwindings. One of these windings 5, is wound on all three poles and is'connected'in shunt between the brush. C and the brush A, a rheostat B,being connected into this circuit for controlling the current in thiswinding in the usual manner.' This winding will control the total fluxin the entirefield circuit and with this winding alone the flux would beequally divided between N and N A second field '6, is shown wound onlyon the poles N and 2 and-connected in shunt between the brushes O and Awith the rheostat R in circuit. The effect of this winding is toincrease the flux in N and decrease that in N thereby producing a higherThe potential between the brushes B and C and a lower potential betweenthe brushes A and C, than would otherwise exist. The third winding the'brush A and the .conductor 2. The turns of this winding on the poles Nand 'N are so designed as to decrease the flux in N and increase that inN 2 upon increase of current in this winding. The increasing saturationof N 2 and decreasin of N mi ht eflect a decrease 1n the total flux in1% and N combined, under these conditions, but the turns of this windingon pole S are so designed as to .tend to increase the total flux andcounteract this effect. By reference to Fi 2, herein later described, itwill be seen t at an increase in the flux in pole N accompanied by adecrease in the flux in the pole N, (the flux in S remaining constant)will increase the potential between the brushes C and A and saturationdecrease the potential between the brushes C and B.

Referring to the train line conductors 1, is a high potential conductorused for charging the storage batteries on the various cars. Conductor'2, is a conductor su lied with lower potential suitablev for t e ampson the various cars. Conductor 4, constitutes a common return for thecurrent of both the lamps and the batteries. Conductor 3, extendsthrough the entire train from the brush C of the generator and connectsto conductor 4, at a point V, at the extreme end of the train, but isnot connected to any apparatus in the cars at intermediate points. Adouble pole automatic switch T, is shown for automatically making andbreaking connection between conductors 2, and 3, and the correspondingbrushes A and C of the generator. This switchisoperated by solenoids 8,9, and 10, acting on a magnetic core L hen the conductors 4, and 3, areconnected at the point V, the coils 8 and 9 will be connected 1n seriesacross the circuits 1-3, with the resistance R inserted in series withthe coils. These coils are so designed that when the total potentialacross the circuit 1-3, reaches a certain desired point the windings 8and 9, will exert a sufficient pull on the core U to close the switchand make connection between the generator and the circuits 2 and 3 onthe cars. As soon as this switch is closed, current will flow throughthe coil 10, for supplying the lamps and char ing the batteries on thecars and the effect of current in this coil will be to hold the switchmore firmly in the closed position, at the same time the coil 9, will beshort circuited, leaving the coil 8, operative to hold the switch int-he closed position so long as the otential across the conductors l-L,in COIIJUIlCi-IOII with the current in coil 10, is sufficient.

Should the common return circuit comprising conductors 3 and 4, beinterrupted at some point, as V, between the lamps and the generator,while the switch T, is open, there would be no current in coils 8, 9, or10, and the switch T would not close. Should this interru tion occurwhile the switch T, is closed, 0 y the coil 8 would be energized andthisalone would not be sufficient to hold the switch T, in the closedposition, and it would immediately open.

On each car is shown a storage battery G and a lamp circuit L. Thelatter is connected directly across the conductors 2, and

4; one terminal of the battery is connected,

to conductor 4, while the other terminal is connected to the lever J, ofan automatic switch. This switch is controlled by the coils H and I,wound on a magnetic core P. The coil I, is connected between theconductors 1 and 2, and when there is sufficient difference of voltagebetween these two conductors the current in the coil I will besufficient to overcome the force of the spring 0 and draw the lever Jinto contact with the contact point K, permitting current to flow fromconductor 1, through the coil H, and

the lever J, into the battery in charging direction. The current thusflowing through the coil H will serve to hold the lever J, more firmlyin contact with the contact oint K. Should the potential between 1 an 2,fall, thus reducing the current in the coil I and also the chargingcurrent in the coil H, sufficiently, the sprin 0, will overcome the pullof the core P an the lever J, will be drawn into contact with thecontact point M, thereby connecting the battery directly across thecircuit 24, to which the lamp circuit L, is

connected.

The general method of operation of the system above described is asfollows: When the cars are disconnected from the generator there will beno difference of potential between the conductors 1 and 2, and no sourceof charging current for the batteries and thereby the lever J will beheld in contact with the contact point- M and the batteries will besupplying the current required by the lamps. If connections are made atthe coupler X, between the generating ap aratus and the balance of thetrain, with t e switch T open, no change will occur at the automatic carswitches, since there will still be no difference of potential betweenthe conductors 1 and 2, and therefore nocurrent in the coils I. When,however, the potential developed at the generator, between brushes C andB is sufficient to close the switch T by reason of the current in thecoils 8 and 9, a difference of potential will immediately be establishedbe tween the conductors 1 and 2, for the reason that the excitationproduced by the field coils 6, on the generator will cause a differenceof magnetic flux in the poles X and X and therefore a difference ofpotential between the brushes A and B. This difference of potential willsend current through the coils I, drawing the lever J, into contact withthe contact point K. The batteries will then be connected between theconductor 4 and the high potential conductor 1 and will receive chargingcurrent. The current required by the lamps in the lamp circuit L will befurnished from the conductors 24, fed by the brushes A and C. Thecurrent in the lamp circuit under these conditions will flow from thebrush A through the series winding 7 on the generator and the effect ofthis series winding will be to increase the potential across the brushesC and A and to decrease the potential across the brushes B and C andthis effect will be proportional to the current required by the lamps.The increase of potential across the brushes C and A maybe made tocompensate for the line drop in the conductors 2, 3, and 4, thusmaintaining aptential across the brushes B and!) will reduce thecharging current fed to the batteries thus tending to compensate for theincrease in current required by the lamps and prevent an overload on thegenerator, which might otherwise result from such increase in current.

Fig. 2, illustrates diagrammatically in the usual manner the method ofwinding the armature of the generator, shown in Fig. 1. Rectangularareas S, N and N represent the pole faceslof the generator, while A, B,and C, represent vthe three brushes. Starting from the point 11, in thearmature winding under brush B and following the winding through. theconductors a, b, c, d, e, f, g,' h, 'i,.'7',

to the point 12 under the brush B, it will be noted that this ortion ofthe armature winding is affected y the flux in poles'N and S only, andthat the elect'ro-motive-force developed in each of the conductors underthe pole faces will be cumulative and produce a total electro motiveforce between the the total flux in S and N brushes B and C,proportional tothe sum of the magnetic flux in- S and that in NSimilarly it will be seen that the potential between v the brushes C andA will be proportional to v On the other hand the. otential between thebrushes A and -B, wil be proportional'to the difference between the fluxin N and that in N It will be noted also that the conductors 7c and m,which constitute the armature coilshort' circuited by the brush B, arepassing through the neutral area between the pole faces and aretherefore developing no electro-motiveforce. The same is true of the.coils short 40 circuited by the brushes C and A; This arrangement willthereforepermit satisfactory commutation to besecured.

I do not claim herein' the generator by itself, as it is made thesubject-matter of my application Serial No. 380,009, filed June 21st,1907, but a I What I do claim as my invention and de' sire to secure. byLetters Patent is 1 In combination a direct current gen erator adaptedto develop two different voltages from a single armature .winding andcommutator; three brushes bearing on the commutator, whereof two arearranged to collect current at two different potentials --with respectto the third; three conductors constituting a high potential and a lowpotential circuit with a common return, automatic means for makingconnectionbe'-.

tween circuits and brushes when the po tential of the generator exceedsa certain limit; translating devices connected between the lowpotentialconductor and the common return; a storage battery connected at oneterminal to the common return; and means adapted to connect the otherbattery The decrease in the p0 terminal to the high potential conductorWhen the difference of potential between the high and low potentialconductors exceeds a certain limit, and at other times to the lowpotential conductor.

coils between any pair of brushes are acted upon by the flux in only twopoles in each group of three; in combination with approprlatecircuits,translating devices and storage batteries'and switches adapted to makeconnection between translatin devices, bat teries' and brushes whereby te translatin devices may be 0 erated from one otential wllllen thebattenes are charged from the ot er.

'3. A source of direct current provided with three terminals and ada tedto develop two voltages of like polarity ut differing in amount betweenone of said terminals and the other two respectively, three conductorsconstituting a hi h potential and a low potential circuit with a commonreturn and adapted for connection to the corresponding terminals of thesource; automatic .means for making connection between terminals andcircuits when the potential of the source exceeds acertainlim1t;*translating devices connected between the 'low potentialconductor and the common return; a storage battery connected at oneterminal with the common return; and automatic means for connecting theother battery terminal to the a high potential con'ductdi' when thedifference ofpotent'ia'l between the high and low potent'a conductorsexceeds a certain limit, and

at other times to the low potential conductor. 4; In combination asource of electric current provided ,with suitable terminals, aconsumption circuit including appropriate conductors andtranslating'devices, a switch for connecting the source to thecircuit,an electro-magnetic device for operating said switch,

.and two coils for operatlng said device, connected in series across theterminals of the source by means of a portion of one of the conductorsfof the consumption circuit,

whereby a break in said portion-will prevent the closingof the switch. x

5. A source of electriccurrent provided -with suitable terminalsa'consumption circuit including appropriate conductors and translatingdevices, means for connecting the circuitto the source'including a.switch for connecting one of said conductors to the switch, the point ofconnection to the transcorresponding terminal of the source, an i latingdevices.

electro-magnetic device for closing said In testimony whereof I havehereunto switch, two coils for operating said device, signed my name inthe'presence of two wit- 5 whereof one is connect-ed between saidternesses.

niinal of the source and a point on said conductor in proximity to saidswitch, andthe other is connectedbetween a terminal of said Witnesses:

source of opposite polarity, and a point on i F. E. FRENCH, 10 saidconductor beyond, with respect to the I W. J JACKSON.

JOSEPH LESTER \YOODBRIDGE.

